Biological behavior body fluids

The ability of a parasite to move to different sites in its host and to maintain its position in host body fluids, where appropriate, is crucial to the parasite s survival. Understanding the mechanisms underlying its motile capabilities, particularly at the level of its neuromuscular system, is of great importance both for an understanding of basic parasite behavior and biology and for the development of anthelmintic compounds. This chapter will focus on the chemical signals affecting the neuromuscular systems of adult parasitic helminths with emphasis on putative transmitters and modulators in the trematodes, cestodes and nematodes. 

Helicoidally isotropic particles furnish the simplest examples of bodies manifesting screw-like behavior. These particles are isotropic, in that their properties are the same in all directions. Yet they possess a sense, and spin as they settle in a fluid. These ideas are likely to be of interest to microbiologists, biophysicists, geneticists, and others in the life sciences for whom handedness and life are intimately intertwined. The microscopic dimensions of the objects of interest to them insures ipso facto that the motion takes place at very small Reynolds numbers. Readers interested in an elementary but broad survey of sense in the physical and biological sciences are referred to Gardner s delightful book The Ambidextrous Universe (Gl). 

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